


The Soulmates Theory

by lostinfictives



Category: Supernatural
Genre: Alternate Universe, Alternate Universe - College/University, Alternate Universe - Roommates/Housemates, Alternate Universe - Soulmates, Angst, At least I already killed off John Winchester in Chapter 2, Castiel and Dean Winchester are Roommates, Childhood Friends, Domestic Fluff, F/F, F/M, Friends to Lovers, Heavy Angst, M/M, Platonic Soulmates, Romantic Soulmates, Roommates, Soulmates, What happens when soulmates fuck it up, this isn't going to be pretty
Language: English
Status: In-Progress
Published: 2021-02-26
Updated: 2021-03-04
Packaged: 2021-03-17 13:49:28
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,438
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29718147
Author URL: https://archiveofourown.org/users/lostinfictives/pseuds/lostinfictives
Summary: This story doesn't end well.  After all, even soulmates can fuck it up sometimes.
Relationships: Castiel/Dean Winchester, Castiel/Mick Davies, Charlie Bradbury/Jo Harvelle, Ellen Harvelle/Bobby Singer, Lee Webb/Dean Winchester





	1. The Romantic

**Author's Note:**

> Thank you so much for clicking on this! Enjoy reading, and, well, I'm sorry.

Castiel sets his glass down with a loud _thump._ Lemon juice splashes against the rim and spills down the cylinder, soaking into the napkin he is using as a coaster. He pays it no mind and wipes his mouth with the back of his hand. Dean follows the gesture with a glint in his eye.

Dean has been listening to his best friend talk about Plato's Symposium for about half an hour. Cas is on a roll, and Dean knows better than to interrupt him and therefore just stays quiet while painting his canvas with a watered-down shade of blue.

Dean steps back, studying the shadows his abstract created. He picks up the palette and mixes a bit of red with white, and Cas speaks.

"Isn't it romantic?" His cerulean eyes are wide and eager, mouth spreading into a grin.

Apparently, during Cas's impromptu research last night, he stumbled upon a chapter of The Spaces in Between by Leng de Chavez, a story published online that's about a slow burn romance between two best friends. Cas ended up reading more than half of the book, and Dean had to snap his fingers a few times to stop him from going off on a tangent about it.

"I mean, sure, the last two are quite sad, but what even is love without a bit of angst?"

According to Zade, one of the main characters in the book, there are three types of soulmates.

_Zade's Soulmates Theory:_

_#1: The lucky ones. Those soulmates who know from the very first meeting that they are made for each other, and nothing and no one can ever come between them and tear the relationship apart._

_#2: The martyrs. They're the ones who settle with just the thought that someone's out there, but they can never be together because choosing others will be more fulfilling._

_#3: The chess pieces. Fate is the game's cruel master. They're the ones who never seem to work things out. They have this connection that no one can ever top, but there are lots of hindrances, mostly personal barriers, that keep them apart. This is the more frustrating one due to the unpredictability of its end game. It often takes them a very long time to find genuine happiness and contentment._

Dean switches brushes and purses his lips. "I don't agree with it," he says carefully. Cas quickly changes his sitting position and perks up closer to Dean's side. "What? Why?" he questions, gaze laced with a bit of accusation.

Dean sighs and completely abandons his work, sitting down next to Cas. He knows his best friend won't let his opposition slide without proper justification, so he might as well get comfortable if they're going to discuss this.

"I don't know, Cas. This theory you're so fascinated about tells us that soulmates are composed of only two people, right?"

It is a rhetorical question, but Cas chimes in, anyway. "Yeah, and oh, boy, I think I know where you're going with this."

Dean continues, "That's my issue with it. Don't get me wrong because I do admire the romantics, and I respect their stance. I just don't agree with this specifically."

Cas surprises Dean by staying quiet, expression mirroring blatant amusement. He quirks up an eyebrow, and Dean resumes. "I just find it dreadful, the thought of having only one soulmate, and the idea that one can never be whole unless they find their sole other half has many negative implications."

Dean pauses and takes a sip of Castiel's lemonade, forcing himself to not spit the juice out immediately. He grimaces and internally scolds himself for forgetting his best friend hates sweets and rarely consumes sugar. Cas chuckles.

"You could've put honey in this, you know?" Cas only laughs and hands the poor boy some napkins.

"Dean, are you sure you've never read that book?"

"Positive. Why?"

Cas hums, nodding a little. "Because Andreau says the same thing as you."

"Andreau?" Dean asks, making his way back to his unfinished painting.

"Mhm. The other main character. He also disagrees with Zade's theory. His argument is basically the same as yours."

"Huh," Dean muses, suddenly intrigued. "Wanna elaborate on that?"

"Well, someone got curious."

"Yeah, yeah. Are you gonna tell me or what?"

"I will!" Cas claps. "Okay, so, Andreau thinks that the sole soulmate thing is quite morbid..."

"Well, he's right," Dean interrupts.

"...says the idea prompts people to focus on the search rather than the relationship."

Dean extends both arms toward Cas, face lightening up. "Exactly, Cas!" he exclaims. "See? That theory will only lead people to seek out perfection rather than what's real and passionate. Uncertainty will always rise to the point where no one will ever be good enough. And a person alone is not going to complete you. That's just shallow, don't you think?"

Dean grabs Cas's hand and yanks him by his side, the canvas sitting still in front of them. He paints strips of red and blue on a vacant space and points at them.

"Assume that this red and this blue are persons. I don't know about you, but they already look whole to me separately. Now see this." Dean paints red over a bit of the blue, creating a vibrant violet color. "Blue and red overlap and create a more complex color that they could've never made alone. Together, they create something new, and yet they remain whole as individuals. With only one interaction with only one other color, they make one discovery. But when I paint yellow over another bit of the blue," Dean does so, "we now have the color green. When I paint red over a little of the yellow," he does so again, "the color orange appears. Do you get what I mean, Cas? If we only ever let one person in because we believe they're our only soulmate, we'll get stuck with a single experience. We will never grow. We make ourselves whole, but the people we let ourselves love, be it platonically or romantically, contribute to our maturity. If you look it up, I'm sure it'll say that a soulmate is someone with whom you feel a profound connection, and I agree. All I'm saying is, you don't have to feel that with just _one_ person."

Dean crosses his arms and looks over at his best friend whose mouth slightly hangs open. "Holy shit," Cas finally says after a beat, "I'm best friends with fucking Andreau Cortez."

Dean furrows his eyebrows as Cas giggles. "Wow, Dean. Sometimes I forget how smart you really are."

"Shut up, Mr. Valedictorian."

"No, I'm serious. I mean, yeah, I already knew about Andreau's reasoning, but the way you explained it yourself was just as deep and creative."

Dean smiles, his cheeks the color of roses. He values his best friend's compliments a lot because aside from Cas being one of the most important people in his life, the boy's a genius. His opinions always matter to Dean.

"I have a question, though," Dean says, "why didn't you just tell me about this Andreau's opinion instead of going on and on about the soulmates theory?"

"Alright, you caught me." Cas smiles, raising his hands up in surrender. "I didn't wanna tell you. I didn't expect you to actually ponder about my ramblings. I thought you'd be busy with your painting. I just, I don't know, maybe want to dwell on the romanticism of having one true soulmate. Thanks for ruining that, by the way."

Dean laughs. "Hey, I always listen to you, and it doesn't have to be _not_ romantic anymore, you know? As I said, you learn new things in every person you meet and love, and yes, you might end up getting hurt by them at some point, but you know what old people like Ellen and Bobby say—with every heartbreak, you're one step closer to your absolute happiness."

Cas can't help but throw his head back, laughing. "It's very nice of you to name drop, Dee." Dean puts a finger over his mouth and shushes, but the other boy only laughs harder that tears threaten to escape his eyes.

When Cas calms down, he says with utmost sincerity, "I love talking to you, Dean. You always have something wise to say. Sam will surely learn a lot from you."

"Now don't get too sappy on me, Cas. Thanks, though. I love talking to you, too." And as though Dean has just gotten an epiphany, his eyes widen. "Hey," he nudges on Cas's side, "maybe we're platonic soulmates!" He exclaims in pure delight.

All of a sudden, there is a shift in Castiel's demeanor, but he is so quick to cover it up with a wide smile and crinkling eyes that Dean almost misses it. He doesn't. Dean creases his forehead in concern, but then Cas is embracing his arm and turning them to face the kitchen where Ellen and Bobby are playing Scrabble.

"Maybe we are," Cas says and then changes the topic, "Okay, but just humor me. Ellen and Bobby. Soulmates #2?"

Dean hums, still wary of Cas's mood change. "Yeah, soulmates #2," he concurs. "I hope they progress, though."

Cas snickers, and Dean quiets him down when Ellen raises an eyebrow toward them.

The whole morning goes by fast, and the next thing Cas knows, he's in the kitchen, helping Ellen bake a Shepherd's pie, Sam and Bobby are watching a soccer game on the television, and Dean is saying goodbye to go pick up Lee for their date this afternoon. Cas waves back before Dean exits the kitchen, and if Ellen notices how Cas stares for a few more seconds at the spot where his best friend disappeared, she doesn't say a thing.

The afternoon goes by even faster. After helping Ellen in the kitchen, Cas joins Sam and Bobby who are now watching a car race with much intensity and occasional shouts and loud remarks that Ellen has to hush them down several times.

When Cas gets bored, he decides to annoy Sam by bombarding him with questions about cars. If there's one thing the younger Winchester hates the most, it's getting interrupted when he's too focused on something. Castiel understands this, of course, because he's practically the same, but what the hell, he's bored, and car things genuinely confuse him.

Cas gets his victory. By the end of the third lap, Sam has gotten too annoyed and turns the TV off. However, his win doesn't last long for Sam immediately decides that if he can't watch his show in peace, he can just poke fun at Cas for his lack of car knowledge.

Sam and Cas bicker so intensely that even though it's all just a joke, Bobby feels the need to intervene. "Son, I don't think we have the right to question Cas's intelligence. I think you're forgetting he's about to graduate as Valedictorian this year."

Cas grins at Bobby.

"But Bobby," Sam says, tilting his head back, "Cas can't even use that against me. I'm also at the top of my whole class, you know?" Cas and Bobby laugh, and Sam groans.

"He's right, though, Bobby, isn't he? The Winchesters are so smart that more often than not, they're just insufferable little shits."

"Language, Cas!" Sam scolds. "Yeah, yeah," Cas giggles, reaching out to mess with Sam's hair, "You're going to change the world someday, Sammy." Sam looks up and smiles. Cas smiles back and reaches down to fix the little boy's hair.

When dinner time comes, they all crowd around the dining table, anticipating Ellen's excellent cooking. As they all sit down, Cas asks if Dean will be joining them, and as if on cue, the roar of the Impala sounds from the driveway. He stands up to greet his best friend, but Dean storms in through the front door as soon as the engine stops and heads straight upstairs, probably to his room. There is heaviness in his footsteps that Cas only recognizes every time Dean fights with his father.

Cas paces quickly, but before he can even go upstairs, a gentle hand squeezes his shoulder, arresting his step. "Let him be, for now, Cas. It's better if you—we—talk to him when he's calmed down." Cas nods and lets Ellen usher him back to the dining room.

They eat in silence save for the clatter of utensils and the soft ticking of the clock, but even with the little noise, Cas can still hear Dean crying in his room.

After dinner, Bobby and Sam wash the dishes while Ellen prepares a plate of food and a glass of cold water for Dean. She gives the tray to Cas, and he balances it in his hands as he makes his way upstairs.

The room is silent when Cas knocks. He knocks twice, thrice, but there's no answer. He knows Dean isn't asleep yet because of the lack of soft snoring on the other side of the door, and so, Cas talks.

"Dean?" His voice is soft, hushed. "Hey, I know you're still up. I brought food. We reckon you could be hungry. Ellen's casserole is as satisfying as ever!"

Silence. Cas puts the tray down and leans onto the door. He sighs. "Look, I won't force you to say anything, okay? Just know that whenever you're ready, I'm here. I'm always here. Well, actually, I'm about to head out, but you know what I mean. Call me, okay? Anytime. And your family's also here, of course. You can always—"

The door opens abruptly, revealing a pretty messed up Dean who hasn't yet to change clothes. He throws himself at Cas and hugs him tightly, knocking over the glass of water on the floor. Castiel hugs him back just as tight, rubbing comforting circles against his back as Dean cries quietly on his shoulder.

"It's alright, Dean. It's gonna be fine. You're gonna be fine."

Cas decides, right then and there, that he's willing to stay however long Dean needs him to. It doesn't matter if Dean's weight grows heavy against his body. It doesn't matter if his shirt gets all wet with tears. It doesn't matter if being his best friend is all Cas will ever be to Dean. It doesn't matter if his love is unrequited. It doesn't matter if Dean falls in love with someone else, and Cas watches. It doesn't matter. Dean said it himself. They are soulmates. It doesn't matter that it's platonic. They will help each other grow, and Cas will stay through it all.

**Notes for the Chapter:**

> The Spaces in Between by Leng de Chavez is a real published work. You can find it on Wattpad, though it's written in Tagalog-English. Zade's Soulmates Theory is in Chapter 39: Of Soulmates and Venn Diagrams.


	2. Lost Boy

**Notes for the Chapter:**

> Trigger warning for death, abusive household, and implied (?) self-harm.

Castiel steps out of the elevator and is immediately alarmed by the loud crashing sound coming from the ajar door of his apartment. He moves fast and pushes the door further open. Notebooks and handouts scatter on the floor. The lamp that usually sits on the side table has been knocked off. Charlie is heaving, her face flaming in rage, and Jo is holding her arm as firmly as possible while silent tears trail down her cheeks. Dean stands on the opposite side of the room, avoiding everyone's gaze. He's still in his sweats, shirt wrinkled, hair disheveled. His appearance hasn't changed one bit since Cas left this morning.

"For fuck's sake, Dean," Charlie yells, "look at yourself! You're a mess! We don't even recognize you anymore!"

Cas rushes to Dean's side and squeezes his best friend's hand. "Charlie, what's going on?" 

"Oh, yeah, then there's Cas." Charlie ignores the question, not even bothering to spare Cas a single glance. "Cas who always puts you above everything else, who stays through all your bullshit. And what does he even get out of this? Nothing, Dean! Nothing because you're an ungrateful bastard who drags everyone else down with all your unresolved issues!"

"Charlie, stop!" Cas steps forward as though to shield Dean from their friend's harsh words, his voice sharp as a knife.

"What, Cas? Are you seriously defending him? You know what? Don't answer that. I'm not like you, Castiel. I'm not that kind. I'm tired of all his shit, and I'm gonna call him out for it."

"Charlie, please," Jo pleads, but her girlfriend only steps away from her hold.

"No. This has to stop. Dean, this has to stop. You're not a fucking child anymore! Look at me, Winchester!" Charlie steps closer and pushes Cas out of the way. "Look at me!" Charlie slaps Dean's chest, causing him to stumble backward. Dean looks at her for a split second. His eyes are void. His gaze is lifeless. "Look, maybe we don't matter, but I'm pretty sure your best friend still means a lot to you. You have no idea, haven't you? Of course. Because Cas is a fucking martyr. Well, news flash, Dean, I'm not. I almost told Cas a few times to just leave you, but I still consider you as my friend. Believe it or not, I just wanna help. But you never listen. Cas is the only one who gets through you, but it's so unfair, Dean. I bet you don't even know half of the sacrifices Cas made just for your sake."

"Charlie, please don't," Cas begs, though he can't seem to move his feet to really put a stop to what's about to unfold.

"Cas is like a brother to me, Dean, and I won't let you ruin his life furthermore." Dean finally meets Charlie's eyes. His look is questioning, but before Charlie can even elaborate, Cas is on her side, pulling her away from Dean.

"Charlie, please don't do this," Cas whispers. "Cas, he has to know. Maybe guilt will knock some sense out of him," Charlie says, already poised to march back to where Dean stands unmoving.

"No! Okay, Charlie, just hear me out." Charlie stops and looks back at her friend. Cas exhales, breath shaking with anxiety. "Don't tell him. Let me do it," he says.

Charlie relaxes, her face soft and laced with concern. She sighs. "You know you have to do this, right? I'm begging you, Cas, just let him know." Castiel bites the inside of his cheeks and nods, looking down. "I'll tell him, I promise. Just...please."

Charlie understands Cas's silent request, and with a squeeze on Cas's shoulder and a final hard look in Dean's direction, she exits the apartment.

"I'm sorry for the mess, Cas," Jo says, "I'll help you clean up."

"No, it's fine. It's okay, Jo." Cas forces a smile. "I'll call you and Charlie later, alright?"

Jo nods and follows Charlie's leaving. As soon as the door closes and they're all alone, Cas bends down to pick up the papers, and he notices that they are notes from Dean's missed classes that Charlie probably photocopied. He drops the handouts and sits on the floor completely, shoulders sagged and expression defeated. Castiel feels like crying.

"Cas?" Dean quietly calls. He walks closer to where Cas is slumped on the floor. "What did Charlie mean by that?"

Cas stands and faces him. His eyes look tired, and Dean feels his heart constrict. "I didn't graduate Valedictorian," he starts, voice even. "I lost a lot of sleep trying to help you get at least a passing average that's enough for them to let you graduate. My performance became poor. Once, Miss Missouri caught me sleeping in class. I had my first detention then. Instead of reviewing for finals, I did your extra credit take-homes when you couldn't because you were passed out drunk. I still did well, but obviously, not well enough to solidify my ranking."

"Cas, I'm so sorry," Dean quickly says, his green eyes overflowing with guilt. "I know how hard you worked for four years to get that honor. I'm sorry. I didn't know."

Cas used to always talk about  _ the dream— _ him graduating Valedictorian in high school, getting into a prestigious college with his best friend and their other friends, constantly being on the Dean's list, graduating with high honors, and becoming a published writer. Once all of those happen, only then will he prove to his parents that he's just as good as his older brother, Michael even though he doesn't choose a  _ practical  _ course. And maybe then, he'll be free of their toxic and emotionally abusive household.

Cas has just gotten past the beginning, and Dean's already messed it up for him. Dean feels so ashamed and guilty, he could throw up. He ruined everything for his best friend. He ruined Cas's dream. "I didn't know," he repeats. "I'm so sorry, Cas."

Cas stares at him and then surprises himself by letting out a scoff. "You didn't know?" he questions, laughing bitterly. "You know I don't blame you for any of that, right? Those were my choices. And if I could go back, I'd do it all over again because I'm your best friend, Dean, and I swore to never leave your side no matter what. But I'm just human. I also get tired. I also have terrible days. My life is far from perfect, and you know that. I was there for you, Dean. I'll _always_ be _here_ for you. I just wish you'd do the same for me like you promised years ago."

A beat. Cas moves and pulls out a chair to properly sit down. Dean remains standing.

"I tried so hard to understand. I told myself you would come around, that you're just going through a loss. But when they called out Valedictorian and I wasn't the one on stage, I looked over at you to seek assurance that even though things didn't happen as planned, it's going to be all okay. I looked over at you, Dean, but you were slumped on your seat, looking like the farthest thing from sober. That's when I realized that my best friend wasn't just going through a loss, rather I lost him. I lost him entirely to grief."

"Cas," Dean says, voice shaking, and when Cas looks up, he can't help but tear up. Dean is silently crying, squeezing his hands together, fingernails digging into his skin. Cas reaches out for his hands and pulls them apart. "Don't do that," he says softly.

"I'm sorry," Dean sobs, unable to look his best friend in the eyes. "I'm sorry, Cas, for everything. I will get better. I promise. Just please, don't give up on me. I can't lose you. I need you."

_ Cas decides, right then and there, that he's willing to stay however long Dean needs him to. _

Cas breathes out. "I want to believe you, Dean. I do, but you say that every time you sober up and wake up to me crying on your bedside. As I said, you don't have to apologize. I still graduated with honors. I got into our dream college with our friends. And you managed to get in as well. See? It's not bad at all. But you, Dean—I think Charlie is right—you're a mess." Cas's heart feels heavy the second he utters the words out. He clenches his jaw and reminds himself that his best friend needs to hear this from him.

Dean bites his lip to imprison a sob. He holds Cas's hands tightly.

"I understand, okay? You went through a terrible breakup. You loved Lee so much, and he broke your heart. Then you lost your dad right after. I know that it's hard for you. I understand."

Everything went downhill when Dean came home that one night, angry and crying. Cas remembers how Dean hugged him so tightly like his entire life depended on him. Lee had just broken up with Dean. They dated for two years, and he was Dean's first everything. Dean's heart was shattered on the floor, and Cas's followed suit, willingly dropping and breaking for him when his heart had no more pieces left to break.

Then one day, Dean received a call from a prison official. His father had been in jail for a charge of fraud by a bank he used to work for. John was immediately proven guilty and got sentenced to 30 years. Dean took the call lightly at first, assuming it was just about his father's shitty behavior, but not long after, Dean dropped the phone, and he fell to the ground, shaking. Cas was by his side almost immediately. John died of a heart attack that morning.

"Dean, I meant it when I said I'll always stay. I'll always be here to help. But my efforts are nothing if you're not even going to try to move forward. You can get through this. You've got to have that belief. Sure, you got your heart broken, but it's not the end of the world. You're young. Someone out there," Cas chokes on his tears, "will love you so much better than he ever did. You said it yourself, remember? One person doesn't make you whole. Lee left, but you're still as intact as you were before you even met him. You just have to realize that again. And with John's passing, I know you have a lot of things you wanted to say to him but never had the chance to. It's not too late. Dean, you haven't even visited his grave since he's been buried. Closure is hard to achieve especially when the other person is gone, but that doesn't mean you'll never have it because you will. You just need to start with yourself. It's hard, but I'm here, Dean." Cas reaches for Dean's face and wipes his tears away. "I'm here," he repeats.

After a moment, they both stop crying, but Dean still holds Cas's hands in his. Cas smiles at him. "You're going to be alright. We'll be alright," he says. "Now, if you really wanna make it up to me, tomorrow morning, wake up at 8, sober up, get your shit together, and attend Professor Macleod's class, you hear me?"

Dean nods, willing himself to look at his best friend and smile back at him. "I'm sorry, Cas," he says again. "I won't disappoint you this time, I promise."

Dean reaches down and buries his face in Cas's shoulder. Cas rubs his back soothingly. "You're gonna be fine, Dean."

"Thank you," Dean breathes.

"Shh, tomorrow will be a lot better. We'll talk to Jo and Charlie, okay?"

"Thank you," he says again.

"You'll always have me, Dean."

"I love you, Cas. Thank you for putting up with me."

"Yeah, you're just lucky I love you, too."

Dean chuckles, and Cas's heart lightens. He hopes this time, his best friend intends to keep his promise.


End file.
